Scroll shears or the like

ABSTRACT

Scroll shears or snips with an offset cutting edge with relation to the flank of the shear, in order to obtain clearance to scroll slightly to the right, while retaining full maneuverability to the left. An adjustable ride or hardened washer interposed between the cutting blades of the shears to facilitate adjustment of clearance after grinding.

United States Patent 1151 3,678,580

Duffy 51 July 25, 1972 [54] SCROLL SHEARS OR THE LIKE 3,143,799 8/l964Gover ..30 259 [72] Inventor: William Duffy, Jamesburg, NJ. FOREGNPATENTS OR APPLICATIONS 1 AssigneeI J- and $9118 Newark, 64,977 ll/l892Germany ..30/26 2] Fl ed Sept 21 1970 Primary Examiner-Ther0n E. Condlon[21] Appl. No.: 74,087 Assistant Examiner-J. C. Peters Art0rne vSparrowand Sparrow [52] [1.8. CI. ..30/267 57] ABSTRACT [51] Int. Cl ..B26b13/28 [58] Field of Search ..30 252, 257, 259, 266, 267 Scroll Shears 9rSnips with an Offset cutting edge with relation to the flank of theshear, in order to obtain clearance to scroll 56] References Citedslightly to the right, while retaining full maneuverability to the left.An adjustable ride or hardened washer interposed UNITED STATES PATENTSbetween the cutting blades of the shears to facilitate adjustment ofclearance after grinding. 642,345 1/1900 Loffi ..30/266 1,594,671 8/1926Isaac ..30/257 10 Claims, 8 Drawing Figures slaw II/ZI PATENTEBJULZSIBIZ 3,678,580

INVENTOR W/ZZI/IM' DUFFY SP/W/Pm/AW Smxwov ATTORNEYS SCROLL SHEARS ORTHE LIKE BACKGROUND OF THE INVENTION The present invention relates ingeneral to shear-type cutting tools and particularly to such tools asare used for cutting metals, plastics and combinations in sheet form.

Scroll shears for cutting sheet metal or like sheet material are wellknown in the trade. They permit unlimited maneuverability in onedirection, so that the operator may cut a square corner, a very smallcurve, or even cycloidal and involute shapes. However, these scrollshears have one serious disadvantage. If shears were made to make ascroll to the left (normal for use by a right-handed person) they wouldnot scroll to the right; thus it was almost impossible to regain a givencutting line when the operator went even slightly off to the left. Thereverse was true when the shears had been made for cutting to the right,so that it had been impossible to return to the cutting line when anerror had been made by veering a bit too much to the right. Improvementshave been made in the past by forging a throat in the flank of theshears, such as disclosed in U.S. Pat. No. 3,143,799. Anotherdisadvantage found in all existing scroll shears is that some metal hasto be removed from the ride area when the blades are resharpened bygrinding, in order to bring the blades back into a proper cuttingrelationship. This is a very difficult, and in many instancesunsuccessful, operation.

A solution to these problems has been found by this inventron.

SUMMARY The invention consists in such novel features, constructionarrangements, combinations of parts and improvements as may be shown anddescribed in connection with the article therein disclosed by way ofexample only and as illustrative of a preferred embodiment.

The novel way to overcome the difficulties and disadvantages of the pastart, which is the gist of this invention, is to provide an offsetcutting edge, relative to the flank of the shears, in order to obtainclearance to scroll slightly to the right while retaining fullmaneuverability to the left. Resharpenin g of worn edges furtherrequires a resetting of the blades in the direction of increasing thespacing of the ride. The invention provides new and very simpleadjusting means for the ride compensation.

Objects and advantages of the invention will be set forth in parthereafter and in part will be obvious herefrom or may be learned bypracticing the invention, the same being realized and attained by meansof the instrumentalities and combinations pointed out in the appendedclaims.

It is an object of the invention to provide scroll shears with an offsetcutting edge in relation to the flank of the shears in order to obtainclearance to scroll slightly to the right while retaining fullmaneuverability to the left.

A further object of the invention is to provide an adjustable ride inscroll shears for permitting adjustments of cutting blade clearance.

Another object of the invention is to provide cutting blade clearanceadjustment means which are easily and conveniently operated.

BRIEF DESCRIPTION OF THE DRAWING In the following description and in theclaims, parts will be identified by specific names for convenience, butsuch names are intended to be as generic in their application to similarparts as the art will permit. Like reference characters denote likeparts in the several figures of the drawing, in which FIG. 1 shows aside elevation of the scroll shears in an open position;

FIG. 1a is a perspective view of the front portion of the shears, withits bottom up;

FIG. 2 is a top view of the scroll shears, partly broken away, shown inFIG. 1, taken in the direction ofthe arrow 2;

FIG. 3 is a bottom view of the scroll shears, partly broken away, shownin FIG. 1, taken in the direction of the arrow 3 in FIG. 2, partlybroken away;

FIG. 4 is a cross-section of the scroll shears shown in FIG. I, takenalong the line 4-4 in FIG. 2, partly broken away",

FIG. 5 is a view of the scroll shears, taken in the direction of thearrow 5 in FIG. 2, partly broken away;

FIG. 6 is a cross-section of the upper blade of the scroll shears, takenalong the line 66 in FIG. I, partly broken off;

FIG. 7 is a cross-section of the lower blade of the scroll shears, takenalong the line 7-7 in FIG. 1, partly broken off.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now in more detail tothe drawing illustrating a preferred embodiment by which the inventionmay be realized, there is in FIG. I a side elevation of the scrollshears 10 with an upper cutting blade 11 and a lower cutting blade 12.Blades 11 and 12 have shanks l3 and 14, respectively and are pivotallymounted on a pivotal bolt 15 (FIG. 4). Blades 11 and 12 have cuttingedges 16 and 17, respectively. Lower blade 12 is offset forwardly offlank portion 14' of shank l4 and extends to the front of upper blade11. Where blade 12 connects at its rear with flank portion I4 it slopesdownwardly as seen at 14". The cutting edge 17 of blade 12 extendsinwardly of the juncture line of blade 12 and flank portion 14. In otherwords, the cutting edge 17 of blade 12 is not in alignment with saidjuncture line, but is offset in relation thereto. Considering theleft-hand scroll shears shown in FIG. 1, shank 14 from which flank 14extends downwardly, is pivoted behind shank 13 and protrudes angularlybelow pivot 15 to the left extending then forwardly to provide blade 12with its cutting edge 17. Upper blade 11 is curved away from cuttingedge 16 (shown at 18 in FIGS. 2 and 5) in order to provide sufficientmaneuverability to the right while retaining capacity for fulloperational movement to the left. The cutting edge 16 of blade 11 is sodisposed on the pivoted shank 13 that the cutting edge 16 meets thecutting edge 17 of blade 12 in a straight cutting line (FIG. 2). Arelief between the lower edge 13 of shank 13 and the starting edge 16constitutes a cutout forming an open space S providing a clearance atthe rear ends of the two cutting edges 16 and 17. Shanks 13, 14 areattached to the handles 19 and 20, respectively, which have hand grips21 and 22, respectively, covered with suitable plastic. Handles 19, 20are extended beyond their point of attachment to shanks l3, 14 in thedirection toward pivot point 15, and their forward ends 23, 24 arepivotally joined by a bolt 25. A spring 26 is wound around bolt 25, andthe free ends 27, 28 of spring 26 are disposed to abut against theinside of shanks 13, 14 in order to urge shears 10 to open, thusproviding a return stroke during cutting operations. A latch 29 isswingably attached to the screw 30 fastening shank 13 to handle 19,whereas the screw 31 fastening shank 14 to handle 20 serves as a catchfor latch 29.

A ride between blades 1], 12 is provided (FIG. 4) consisting of a washer32 which is located in recesses 33, 34 of blades 1 I 12, respectively.Washer 32 preferably consists of hardened steel and is preferably coatedwith a layer 35 of a material having a low coefficient of friction suchas Teflon S." Three pointed set screws, commonly called half dog pointset screws 36 are equally spaced around pivotal bolt 15 and are directlythreaded in lower blade 12 (FIGS. 3 and 4). Set screws 36 abut withtheir dog points against washer 32. It is easily and convenientlypossible to adjust the clearance between blades 1 I, 12 by means of setscrews 36. This facility of adjustment of blades l1, 12 after regrindingthe cutting edges l6, 17 thereof has the further advantage of quickadjustment for cutting very thin material. When cutting an average sheetmetal of 0.020 to 0.036 inch thickness, a clearance of approximately0.008 inch between cutting edges 16 and 17 should be kept. However, whencutting very thin materials of 0.002 to 0.012 inch thickness, theclearance between cutting edges 16 and 17 must be reduced to zero,because otherwise the thin metal is pulled between the blades and issqueezed, chewed or is otherwise improperly cut. Conversely, whencutting very heavy materials of 0.040 to 0.062 inch, a spacing orclearance of approximately 0.012 inch between the cutting edges has beenfound desirable. By the use of the novel ride compensating adjustment,according to the present invention, settings suitable for the work to bedone can be easily and quickly obtained, as well as resetting aftersharpening of the blades.

While the invention has been described and illustrated with respect to acertain preferred example which gives satisfactory results, it will beunderstood by those skilled in the art after understanding the principleof the invention, that various other changes and modifications may bemade without departing from the spirit of the invention.

1 claim:

1. Shears having an upper cutting blade and a lower cutting blade and apivotal bolt, said blades being rotatably disposed on said bolt, saidblades having cutting edges forming a cutting line, said cutting linebeing offset relative to said blades; and a ride between said bladesdisposed to provide cutting clearance between said cutting edges, saidblades having recesses, said ride inserted in said recesses, said rideconcentrically circumposed around said pivotal bolt, and a plurality ofset screws threadably disposed in one of said blades equally spacedaround said bolt, said set screws abutting against said ride wherebysaid cutting clearance between said cutting edges may be adjusted.

2. Shears according to claim 1, said upper blade having a curved shapecurving away from said cutting line.

3. Shears according to claim 1, and wherein said ride is a washer havingan antifriction coating thereon.

4. In shears having an upper cutting blade and a lower cutting blade anda pivotal bolt, said blade having cutting edges and being rotatablydisposed on said bolt; a ride between said blades disposed to providecutting clearance between said cutting edges, said blades havingrecesses, said ride inserted in said recesses, said ride concentricallycircumposed around said pivotal bolt, a plurality of set screwsthreadably disposed in one of said blades equally spaced around saidbolt, said set screws abutting against said ride whereby said cuttingclearance between said cutting edges may be adjusted.

5. In shears according to claim 4 wherein said ride is a washer havingan antifriction coating thereon.

6. Shears having an upper cutting blade and a lower cutting blade and apivotal bolt, said blades being rotatably disposed on said bolt, saidblades having cutting edges forming a cutting line, said cutting linebeing offset relative to said blades; and a ride between said bladesdisposed to provide cutting clearance between said cutting edges, atleast one of said blades having a recess, said ride extending withinsaid recess; said ride concentrically circumposed around said pivotalbolt, and a plurality of set screws threadably disposed in one of saidblades substantially equally spaced around said bolt, said set screwsabutting against said ride whereby said cutting clearance between saidcutting edges may be adjusted.

7. Shears according to claim 6, said upper blade having a curved shapecurving away from said cutting line.

8. Shears according to claim 7, and wherein said ride is a washer havingan antifriction coating thereon.

9. In shears having an upper cutting blade and a lower cutting blade anda pivotal bolt, said blades having cutting edges and being rotatablydisposed on said bolt; a ride between said blades disposed to providecutting clearance between said cutting edges, at least one of saidblades having a recess, said ride extending within said recess, saidride concentrically circumposed around said pivotal bolt, a plurality ofset screws threadedly disposed on one of said blades substantiallyequally spaced around said bolt, said set screws abutting against saidride whereby said cutting clearance between said cutting edges may beadjusted.

10. In shears according to claim 9, wherein said ride is a washer havingan antifriction coating thereon.

1. Shears having an upper cutting blade and a lower cutting blade and apivotal bolt, said blades being rotatably disposed on said bolt, saidblades having cutting edges forming a cutting line, said cutting linebeing offset relative to said blades; and a ride between said bladesdisposed to provide cutting clearance between said cutting edges, saidblades having recesses, said ride inserted in said recesses, said rideconcentrically circumposed around said pivotal bolt, and a plurality ofset screws threadably disposed in one of said blades equally spacedaround said bolt, said set screws abutting against said ride wherebysaid cutting clearance between said cutting edges may be adjusted. 2.Shears according to claim 1, said upper blade having a curved shapecurving away from said cutting line.
 3. Shears according to claim 1, andwherein said ride is a washer having an antifriction coating thereon. 4.In shears having an upper cutting blade and a lower cutting blade and apivotal bolt, said blade having cutting edges and being rotatablydisposed on said bolt; a ride between said blades disposed to providecutting clearance between said cutting edges, said blades havingrecesses, said ride inserted in said recesses, said ride concentricallycircumposed around said pivotal bolt, a plurality of set screwsthreadably disposed in one of said blades equally spaced around saidbolt, said set screws abutting against said ride whereby said cuttingclearance between said cutting edges may be adjusted.
 5. In shearsaccording to claim 4 wherein said ride is a washer having anantifriction coating thereon.
 6. Shears having an upper cutting bladeand a lower cutting blade and a pivotal bolt, said blades beingrotatably disposed on said bolt, said blades having cutting edgesforming a cutting line, said cutting line being offset relative to saidblades; and a ride between said blades disposed to provide cuttingclearance between said cutting edges, at least one of said blades havinga recess, said ride extending within said recess; said rideconcentrically circumposed around said pivotal bolt, and a plurality ofset screws threadably disposed in one of said blades substantiallyequally spaced around said bolt, said set screws abutting against saidride whereby said cutting clearance between said cutting edges may beadjusted.
 7. Shears according to claim 6, said upper blade having acurved shape curving away from said cutting line.
 8. Shears according toclaim 7, and wherein said ride is a washer having an antifrictioncoating thereon.
 9. In shears having an upper cutting blade and a lowercutting blade and a pivotal bolt, said blades having cutting edges andbeing rotatably disposed on said bolt; a ride between said bladesdisposed to provide cutting clearance between said cutting edges, atleast one of said blades having a recess, said ride extending withinsaid recess, said ride concentrically circumposed around said pivotalbolt, a plurality of set screws threadedly disposed on one of saidblades substantially equally spaced around said bolt, said set screwsabutting against said ride whereby said cutting clearance between saidcutting edges may be adjusted.
 10. In shears according to claim 9,wherein said ride is a washer having an antifriction coating thereon.